


Door to the Dark

by sukikobold



Series: Post-pacifist Ending [1]
Category: Undertale (Video Game)
Genre: Adventure, Character Death, Crossing Timelines, Drama, Female Frisk, Friendship, Gen, Maaaaaybe
Language: English
Status: In-Progress
Published: 2015-12-04
Updated: 2016-08-24
Packaged: 2018-05-04 20:33:11
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 9,103
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5347631
Author URL: https://archiveofourown.org/users/sukikobold/pseuds/sukikobold
Summary: <blockquote class="userstuff">
              <p>Almost immediately Frisk's feet found the ground again and she stepped unsteadily onto a floor very different from the laminate tiles of Alphys’s lab. She was standing in the center of a stone room. The portal gave off a soft blue light that couldn’t quite reach the ceiling, but the walls were rounded, like a cavern. This place was almost like…</p><p>“Huh.”</p><p>Frisk looked to her left where Sans was standing.</p><p>“When she told us it was underground, I hadn’t thought she meant THE Underground.”</p>
            </blockquote>





	1. Chapter 1

“Okay…okay…okay? Okay, I-I think we’re good.” Alphys rechecked the readings against her notes half a dozen more times anyway before giving an assuring nod to Frisk and Sans. They were standing in front of a raised platform in the middle of the lab, atop which there was bolted a rectangular metal doorframe. Also atop the platform and circling the frame with a scrutinizing air was Papyrus.

“Yes, yes, good,” he said quietly, stopping in front of it, “That’s very good…what exactly are we trying to do with this again?”

Undyne, who was leaning against the counsel Alphys was working at, rubbed her temples and groaned. “Papyrus, _please_ don’t make her explain it again. We’re testing a magic time door, let’s just leave it at that.”

“Well,” Alphys answered hesitantly, “I-it’s not exactly a ‘time’ door. Though the dimension it leads to was created, well, I hypothesize was created, o-out of a branch of our own time line, thus making many aspects of it similar to our own world, I-I wouldn’t say it travels through time. It more creates a sort of bridge using a delicate spot preexisting in the space that divides out simultaneous existences-”

“ _Alphys!_ ” Undyne interjected, covering the fins where ears would have been on a human, “Please, the nerd talk…”

As Alphys began to apologize, Sans spoke over them, “It’s a magic time door.”

“And it’s…safe?” asked Papyrus, his voice still subdued, much unlike the usual loud chatter everyone was used to hearing.

“I’ve tested it with drones about five or six times now. O-only for a few minutes each, but they report that the atmosphere is almost identical to ours and there was no sign of any humans or monsters present. So, I mean, that sounds pretty safe, right?

Papyrus didn’t answer and continued to frown at the doorway. Behind him, Sans’s usual smile fell a little and he glanced to Frisk standing next to him. She caught his look and after a thoughtful pause spoke up. She assured Papyrus that the trip wouldn’t be very long and how they could come out with some important answers, but before she could finish he whirled around on both of them.

“Well, I _still_ don’t see why it has to be you two!”

Sans stifled a sigh and instead shrugged his shoulders. “That’s what we came here for.”

Patiently, Frisk stepped up onto the platform and explained how she had asked Alphys to help her learn more about the strange ability she had. Not long after leaving the Underground, Frisk had confessed to her friends about her apparent power to reset time to particular spots at will. It had been received with confusion and disbelief, but mostly acceptance.

“And- and while I was investigating it,” Alphys chimed in, “I found this weak spot in the fabric of our dimension. I-I don’t know for certain that it’s related to Frisk, but…well, we’re hoping to find that out today!”

After a moment of silence, Papyrus stepped down from the platform, passed behind the two of them and turned back. He was still scowling, but didn’t make any more complaints for the moment.

“Alright Alphys, what’s next?” asked Undyne.

“Well,” Alphys checked the instruments once more, “I think we’re set to go. Oh! Um, I should probably tell you…” She turned towards Frisk and Sans, who had also stepped up on the platform. “The machine isn’t powerful enough to hold the portal open for more than a few minutes. After I let you guys through, I won’t open it back up for another hour. So make sure you stay close by when the hour’s up, alright?”

Frisk nodded as Sans moved to stand next to her in front of the frame.

“O-okay, ready?” asked Alphys one last time before she entered a command into the counsel. There was a crackle of energy from within the doorframe. A tiny spark of light appeared in the center and began to grow slowly larger.

“Hey Sans!” called Undyne, pushing off the counsel, “You’d better bring Frisk back safe or else.” The scowl on her face was only partially joking. Sans shrugged in response, than turned toward Papyrus.

“Relax, Bro. We can handle this.”

Papyrus made no response as he stared at the floor. Nor did he respond when Frisk gave him a reassuring smile and told him they’d be back soon. Then she turned and waved to Alphys and Undyne.

The spark had filled the doorframe with a shimmering bluish field. Frisk glanced over at Sans who gave her a wink before stepping into it. She took in a deep breath and followed. Her skin tingled as if being hit with tiny electrical shocks as she passed through.

Almost immediately her feet found the ground again and she stepped unsteadily onto a floor very different from the laminate tiles of Alphys’s lab. Frisk had involuntarily squeezed her eyes shut when she entered the portal and now opened them. She was standing in the center of a stone room. The portal gave off a soft blue light that couldn’t quite reach the ceiling, but the walls were rounded, like a cavern. The floor was mostly flat but rose into formations near the wall. This place was almost like…

“Huh.”

Frisk looked to her left where Sans was standing.

“When she told us it was underground, I hadn’t thought she meant THE Underground,” he said, scanning the room. Frisk asked if he was sure, because she didn’t remember this area at all.

“Oh yeah. See this?” He gestured to the formations near the walls. At closer inspection, Frisk found that they were carved and painted with various figures and text she couldn’t read. “We’re beneath the castle somewhere. It’s very old and kind of unstable. At least ours was.” He turned and gave her a grin. “Not the sort of place for kids to hang out.”

Suddenly the lighting in the room flashed brighter and there was a crackle of energy. It lasted only an instant before everything was thrown into darkness. Frisk didn’t move. She wasn’t sure if something had gone wrong or that was how the portal was supposed to close. Soon she noticed a heavy breathing in the room, too far behind her to be Sans. Before she could say anything, it rose into a voice.

“Hah…hah…I made it. Nyeh heh heh! Take that, portal! The great Papyrus shall not be bested by the likes of you this day!”

Frisk thought she heard a soft groan from her left, but wasn’t sure.

“Um,” the voice continued meekly, “Sans? Frisk? Are either of you there?”

“Yeah Papyrus, we’re here,” answered Sans in a neutral tone, “Why are _you_ here?”

“Why, to look after my brother and best friend, of course!” answered the great Papyrus, “…You know, when I can see them.”

Frisk laughed. She trusted Sans to look after her of course, but it was a relief having Papyrus there. She had spent far too much of her first adventure alone.

After another moment, she heard Sans speak up. “Just listen. You should be able to _patella_ where we are.”

“SANS!”

“What’s up, Bro? Can’t take a little _pun_ ishment?”

“Oh hey, is it getting lighter?”

“Come on, don’t dodge- oh.”

Papyrus was right. Frisk could begin to make out figures in the dark, slowly being illuminated. She looked up and smiled at the bluish fungi that clung to the walls and were growing brighter by the second.

“Ah, that’s better,” said Papyrus, looking over his now visible surroundings. Frisk waved, though they were only a few feet apart. Papyrus waved back.

“Now that we’ve shed some light on the subject, which way do you want to go, Frisk?” asked Sans. Frisk realized there were three passages that led out of the chamber: one right before them and two more behind. She pointed to the one directly ahead.

“Works for me,” said Sans with a shrug, “That okay with you, Papyrus?”

“What?” Papyrus said, taken off guard “Oh. Y-yes!” He composed himself and straightened his posture. “Of course. I am simply here as an escort. Lead the way, Frisk.”

As they began to walk, Frisk asked Papyrus how Alphys and Undyne had been when he had decided to enter the portal.

“Well, Alphys was pretty focused on her work. I don’t think she noticed. Now, Undyne…” He coughed. “The last thing I heard from her came out very…violent. I should remember to advise her on expressing herself without making death threats when we return.”

As they explored, Frisk began to think how this place was not quite like the Underground she remembered. Rather than a straight shot from one area to the next, the paths branched and curved, frequently leading to dead ends. She soon picked up a sharp stone and began marking the paths they had already taken. Thanks to the fungus, the paths were all well-lit, and though they would sometimes come across trash on the ground or other discarded items, they never met another soul, human or monster.

While walking through a larger chamber, Frisk suddenly stopped and pointed to the rock formations near the wall.

“Oh…hey, you’re right,” said Sans, “This _is_ where we came in.”

“WHAT? You mean we just got turned around?” exclaimed Papyrus.

Frisk pointed out that the tunnel they had just exited from was not the same as where they had entered. Papyrus was not consoled by this.

“Ugh, this place! You can’t tell where you’re going, nobody’s around, and everything’s covered in _dust_! It’s completely-” He stopped. So did Sans. Frisk hadn’t noticed before, but looking down at her shoes she saw that they were, in fact, covered in dust.

“Yeah, well…” Sans looked at Frisk, then back to his brother. “This place is pretty abandoned and decrepit.”

“Ah…Y-yes, that’s right,” continued Papyrus, catching the look, “I’m sure everything would be cleaner if someone was here to take care of it. Yes, that must be the reason!” He gave Frisk what he hoped was a convincing smile. She said nothing.

“Um,” Papyrus spoke up again, “How much time do we have left, Frisk?”

Frisk checked her watch. They had been down there about fifteen minutes.

“Very well! Shall we continue?” He gestured to the final tunnel they had not yet explored.

Unlike the other passages, this one sloped gradually upward and branched out at fewer points. The corridor became wider as they walked, turning into more of a long room than a tunnel. Frisk thought she could feel a soft breeze, but the air smelled stale. The skeletons were walking on either side of her and she noticed Papyrus was hugging his arms.

“What’s up Bro? You can’t be cold, you know, you don’t have skin.”

“I’m not cold, it’s just…this place is creepy. It’s like the Underground but it’s definitely _not_.”

Frisk said she agreed and that it reminded her of the lab beneath Alphys’s house. The one she had explored after Papyrus had called recommending her to do so. She then gave him a brief but pointed look.

“Whoops,” said Sans with a grin, “I think Frisk’s still mad at you about that.”

“I-I told you I didn’t know what would be down there! I thought Alphys just needed some company! Besides, things worked out in the end,” said Papyrus defensively.

Frisk muttered that none of that really mattered to her, and that she only wished he had come down with her instead of sending her in alone.

“Well…” began Papyrus, more softly, “I’m here now, aren’t I?”

Frisk’s annoyed face softened into a smile as she looked up at him. Then he saw it. The shadow of someone and the flash of a long, thin blade suddenly appearing behind her. Papyrus was not quick enough to react, but the shadow was suddenly thrown back into the far wall. Its knife clattered across the floor. Frisk whirled around but Sans caught her shoulder and pulled her back. His free hand was outstretched, aimed at the figure. They rose to their feet and retrieved the weapon as they approached the trio. They only got a few steps before being thrown back again, this time by a wall of bones that appeared and disappeared in a second.

“S-sans?” said Papyrus, and Frisk felt his hand on her shoulder as well.

“Papyrus.” Sans’s voice came out slow and unnatural. “Get Frisk out of here.”

Papyrus looked from his brother back to the figure, knife in hand, regarding them from a distance.

“…Alright.” He knelt and wrapped an arm around Frisk’s legs so he could scoop her up. She didn’t protest, instead watching the figure warily as they backed away.

“Sans? Aren’t you coming?” Papyrus asked in a loud whisper. Sans hadn’t moved from where they had stopped.

“Relax, Bro. Right behind you,” he answered. The figure began approaching once more. Hesitantly, Papyrus turned and began to run down the corridor. Over his shoulder, Frisk watched the retreating image of her friend, still rooted to the same spot, and the person with the knife, who had just broken into a run.


	2. Chapter 2

Papyrus’s long stride took them through the tunnels at a brisk pace. He kept a straight path, only turning when he had to, and kept checking back over his shoulder. Frisk quickly noticed they were going uphill and away from the portal, but she didn’t point it out. Neither she nor Papyrus saw Sans or the figure coming up behind them.

Suddenly they passed through an arch and came out onto a wide open ledge.

“Oh…Frisk, look.”

Frisk turned and saw a vast, familiar sight. An enormous ancient city standing beneath a ceiling of glowing stones that mimicked the night sky. The ledge they stood on hung high above it and they could only see rooftops and darkened streets.

“This really is the Underground,” said Papyrus, as he lowered Frisk to the ground. Then, remembering their current plight, he began to look around for another path. Frisk tugged his arm and pointed to a tall outcropping of rock past the arch they had entered from. The area behind it was blocked from the view of anyone coming out of the passage. They quickly got behind it and sat down to wait. Periodically, Papyrus would lean out to watch the entrance, but no one came.

“Don’t worry, Frisk,” he said eventually, “Sans is very tough, even if he is equally lazy. He’ll be along soon. He probably just got a little lost.” He paused. “Although I _did_ try to take the most obvious path. Hm.” Another pause. He turned to Frisk. “A-anyway, who do you think that was?” Frisk shook her head and pulled her knees to her chest.

Papyrus thought for a moment. “I wonder…do you think they were human? They did look a little like you.”

Frisk hugged her knees closer.

“O-only a little!” Papyrus added quickly, “In a vague, human-like way, you know?”

“And there are billions of humans out there, right?”

Papyrus and Frisk both jumped at the new voice and found Sans now sitting beside them. He was smiling, but Frisk could see tiny beads of sweat on his skull.

“Sans! Where have you been?” Papyrus demanded.

“Bathroom,” said Sans, his grin widening but it didn’t reach his eyes, “I think we lost them for now.”

Frisk asked quietly if he was okay.

“Yep, not a scratch on me.”

She exhaled, relaxing her arms a little. Then she stood up and walked over to the edge of the platform to look over the city.

“Careful”, said Papyrus before turning back to Sans. “Should we head back down?”

“We don’t really have a choice,” said Sans. He massaged his shoulder as if it were sore.

“Well,” began Papyrus with a frown, “Sure they were spooky and weird and possibly violent, but if the three of us faced them together, I’m sure we could get through.”

“Yeah, I’m not sure that will work,” said Sans, the sweat beading up on his skull again, “It’d be best if we could avoid them entirely.”

“Yeah, but we might not be able to.”

Sans sighed. “Okay, let’s use the tunnels if we have to. If we can get enough distance between them and us, that should give us enough time to get back through the portal.”

“Frisk, how much time do we have?” asked Papyrus. He looked up and saw that she was still near the edge, looking at the city.

“Frisk?”

Her head whipped around to look at them, her expression indeterminate. Papyrus repeated the question and she checked her watch. They had about fifteen minutes before the designated time.

“Better get moving,” said Sans, standing.

The three of them reentered the tunnel. In spite of their time limit, they traveled with care and watched both in front and behind. Frisk found herself holding onto Sans’s coat or Papyrus’s arm whenever they passed a side tunnel. They encountered no one, however, and by the time the tunnel slope began to flatten out again they were more relaxed.

“Maybe they went down one of the other tunnels,” suggested Papyrus, “You really did lose them, Sans!”

Sans smiled and shrugged. “Maybe.” But as they neared the first chamber, he held out an arm to stop Frisk, who in turn held out her arm to stop Papyrus.

“What is it?” asked Papyrus. Frisk put a finger to her lips. “What is it?” he repeated in a whisper.

“It’s there,” said Sans, “That _thing_ is standing right where the portal opens.”

“What? Why?” asked Papyrus, panic slipping into his voice.

Frisk stepped forward to look through the entryway. In the center of the chamber she could see the figure. It appeared to be stooped over, carving something into the floor with its knife. She suddenly felt very cold. When Sans touched her shoulder, she flinched. He silently directed them back towards the wall, away from the entrance.

“Do you mean that it” began Papyrus, “It’s _waiting_ to use our portal?”

“That’s what it looks like,” said Sans with a nervous smile.

“Then-then we have to lead them away somehow! Like we talked about earlier, right?”

“Yeah,” said Sans, “And someone’s going to have to go through and tell Alphys to close it.”

Papyrus stood silent for a moment. “Frisk?” he asked. Frisk looked up from where she’d been staring at the ground.

“Sans and I are going to lead the…person through that looping tunnel we went through before. Can you go through the portal and tell Alphys to close it?” Frisk was shaking her head even before he’d finished the question.

“Frisk,” said Sans, “I’m sorry, but we don’t have many options-”

“Fear not, Frisk!” his brother cut in, “I, the great Papyrus, will ensure that we escape and return to you in time!”

“Heh, see? My brother’s got this. We’ll be fine.”

Frisk looked from one skeleton to the other, then back to the floor. Slowly she nodded.

Papyrus was the first to go out, in spite of his brother’s initial protests. He claimed to be “unmatched in the art of distraction”.

“Excuse me!” she could hear him shouting, “Yes you! Um…You, Individual! I don’t believe we have been introduced!” Sans waited until his brother’s voice moved further into the room, then gave Frisk a final grin and a “See you soon” before following.

She stood there quietly, not daring to look out until all of their footsteps had faded, lest she ruined the plan. When she did enter, the chamber looked exactly as it had when they arrived; empty and abandoned. The fungi seemed to be shining dimmer than before. She checked the time. Three minutes left. Was that enough time for them to get back? What if they got lost themselves? What if they were… Frisk shook her head. She had to trust them.

The minutes dragged on as she stood there in the center of the room, waiting. Finally she heard a soft crackle. Like electricity. A bright spark appeared in the air and grew. The fungi dimmed as it brightened, until it was almost painful for her to look at. She continued to wait. She knew the portal was unstable and their window was small, but she couldn’t take that step. Not without…

“FRISK!”

Frisk whirled towards the tunnel the voice had come out of. There was Papyrus. He was trotting towards her, beaming and looking only slightly out of breath.

“It’s open? Great!” He slowed as he approached, still talking. “We lost them, I think. It was pretty easy actually. I almost thought they might have turned around, but here you are. Sans should be right behind-”

He flinched. Frisk couldn’t tell why until she looked down and saw the shining piece of metal piercing out of his chest. Her hands flew to her mouth. Papyrus looked down as well, confused.

“O-oh. Um.” He looked back up and saw her expression, then raised his hands as if to calm her. “Whoops. I-it’s okay, Frisk. See? I’m fine. I-”

The blade moved sideways, ripping his torso open and silencing his cry of pain as soon as it began. His body didn’t even have time to fall before it dissolved into a cloud of dust and cascaded across the floor.

Frisk couldn’t breathe. The person standing behind the falling dust, the person who shared her face, watched it spread for barely another second before they looked up at her. They stepped forward.

Then suddenly they weren’t there. They had been thrown into the air by an invisible force. She saw them land at the other end of the chamber. Then she couldn’t see much of anything. The room was filled with bones and giant skulls in a shape she might have seen before but couldn’t think where. Amidst the chaos of moving white shapes, Frisk thought she saw a splash of blue. She tried to call Sans’s name, but her voice was lost in the noise of magical blasts and impacts she couldn’t see. Frisk looked towards the portal. Its edges were starting to waver and spark as the field rippled from the center.

_Back._

She turned back to the chaos. She couldn’t see anything. Not Sans. Not Papyrus.

_Go back._

Her vision began to blur and she pressed her hands over her eyes.

 _RESET_.


	3. Chapter 3

 “Frisk, how much time do we have?”

Frisk opened her eyes. She was standing near the edge of the plateau. Below her, the ancient city sprawled out to the ends of the Underground, filling her with…

“Frisk?”

She didn’t turn, instead swallowing the lump in her throat. She was shaking. The sight of the city before her began to quiver as water filled her vision. She heard steps behind her, and as a hand touched her arm, the tears spilled from her eyes. The confusion on Papyrus’s face when he turned her around was instantly replaced with panicked concern.

“Frisk?” He held her shoulders and bent down to see her face. “Frisk, what’s the matter?”

She broke. With a sob she leaned into him and wrapped her arms around his waist. He rested a gloved hand on her head and put the other around her shoulders.

“Frisk…It’s okay, I’m here.”

She continued to cry shakily, and more noisily than she wanted to. As she did a third hand began to rub her back.

“Hey…” said Sans softly.

Gulping back her sobs, Frisk tried to calm down. They didn’t have time for this. She had to figure something out, fast. Pulling back, she rubbed her face and tried to think.

The skeleton brothers exchanged looks of confusion as Frisk’s gasps subsided. Sans turned her towards him and wiped away the remaining tears.

“Listen, we’ll make it out of here, okay? I promise. We’ve got a plan.”

Frisk’s face was filled with such a look of panic he lost his words for a moment. Then she looked over to Papyrus who stood there, quiet and concerned. Sans followed her gaze and expression, and after a moment spoke again.

“…It didn’t work, did it?”

Frisk swallowed and shook her head.

“What? What happened?” asked Papyrus, still at a loss as to what had caused his friend so much distress. Sans furrowed his brow and looked down.

“We have to come up with a new plan.”

“We do?”

Quietly, Frisk told them how the figure with the knife would be waiting for them where the portal appeared.

“What? Why?” asked Papyrus, panic slipping into his voice.

Sans swept a hand over his eyes. “That’s gonna be a problem.”

“Well,” said Papyrus, “Can’t we still just lead them away and head back in time, like we were-” He stopped as Frisk grabbed his arm, shaking her head violently. “Oh…a-alright.” He tried to give her a comforting smile. “We’ll just…think of something else, I guess.” He looked to Sans for help, but his brother seemed deep in his own thoughts.

“I…I don’t really _want_ to hurt them, but maybe if we pushed them back enough, that could give us an opportunity?” Papyrus suggested.

Sans exhaled slowly and looked up. “Maybe. Frisk doesn’t fight, though.”

“I know _that_ ,” said Papyrus, “But she’s really good at dodging.” Frisk smiled a little. Then commented that it was an idea, but she didn’t think they would be able to keep it up for long.

“Then we wait until the last minute?” offered Sans.

“Certainly! With our combined strength, I’m sure we can do it!”

Sans looked questioningly at Frisk, waiting for her assessment. She only stated that it might work and that they didn’t have much time.

“In that case…Frisk, how much time do we have?”

She checked. Ten minutes.

“Better get moving,” said Sans.

They entered the tunnel, wary but with purpose. Frisk soon reached over to hold on to Papyrus’s arm as they walked. He looked at her curiously, but made no comment. They moved quickly, not bothering to check side tunnels as they traveled straight down. It wasn’t long before the tunnel floor began to flatten out again.

“Are they in there?” asked Papyrus quietly as Sans approached the entrance.

“Yeah,” said Sans, “Frisk was right.”

Frisk tightened her grip on Papyrus’s arm. She asked how they were going to do this.

Sans leaned back against the wall and wiped his forehead. “I…I’m not really sure. Papyrus and I could use magic attacks from a distance, maybe distract them. Frisk…maybe you should stay back here until the portal opens.”

Frisk released Papyrus’s arm and told him that she would not. She then told them that in her journey through the Underground she saw more fighting and survived more battles than the both of them.

“That is true,” admitted Papyrus, “And she IS good at dodging. Very well, I shall lead the distraction.” He turned and headed purposefully towards the cavern. Sans caught his arm.

“Wait,” he said, “I’ll go out first.”

“What, on your own?”

“Give me just a moment to confuse them. Then you can follow.”

“Sans,” Papyrus said, bringing his brows together, “I’m not sure you’d be best in the front line.”

Sans shot a glance back at Frisk before continuing. “I’ll be fine. We shouldn’t start with our best weapon you know.” He smiled, trying to make the situation lighter.

“We’re trying to stall, not win. Of course we should try to catch them off guard!”

Sans’s smile vanished and he tried to explain how it would be better for Papyrus to follow. They continued like this, Papyrus insisting on his own capability of handling the task and Sans growing increasingly distressed over the idea of his brother leading. In the middle, Frisk stepped around them to look inside the cavern. After scanning the blue-lit room, however, she quickly interrupted the brothers.

“Gone?” asked Papyrus, “Are you sure?”

The two of them followed to look out with her, but the cavern appeared to be empty.

“Do you…do you think they went further inside?” asked Papyrus

“Careful,” was all Sans responded with.

After a minute or so of no activity, they entered together, none of them daring to speak once they were inside. Frisk quickly checked her watch. The portal was due to open any second.  Ahead of them, a tiny glimmer of light appeared in the air and began to grow. Frisk silently grabbed the hands of the skeletons and began to head towards it. The fungi darkened as the light expanded, until they went out completely.

As the portal filled up, Frisk stopped. In front of it there stood a person, silhouetted by the edge of the field of light. Frisk hadn’t seen when they’d appeared, but there they were. Papyrus was the first to let go of her hand. He stepped forward. Bones, tall and thin, flew before him, sliding along the ground towards their opponent. They dodged. They dodged very well, sidestepping and jumping to avoid the attacks. Then other bones appeared to accompany the first, smaller and more numerous. They fell in waves upon the attacker. White, then blue, then white again.

Frisk stood behind Sans and Papyrus as they attacked, feeling more than a little useless. Between the rows of bones spreading ahead of her, she could see the person moving through them. And getting closer. Suddenly the attacker was right on top of them, flying towards their group with their knife outstretched. They split, Papyrus and Frisk to the right and Sans to the left. All three of them used the opportunity to dash towards the portal. But the room was wide, and Frisk found herself falling gradually behind her friends as they ran. She heard footsteps almost identical to her own catching up quickly. She sidestepped and narrowly avoided falling on her face as the knife came down where she had just been. Now the figure, the human, was on her tail. She ran and tried to circle back towards the portal, but the human followed just as quickly, pushing her away from it every step. She was being forced further and further towards the wall and running out of room.

Suddenly the knife was coming down again and Frisk flew to her right. She slammed into the wall and saw the knife change directions, heading straight towards her face. Frisk squeezed her eyes shut and heard the crack of the knife hitting something hard. When she opened them again, a wall of blue bones had grown up from the ground and back into the cave wall, forming a tightly-knit cage around her. The human wrenched the knife out of the bone, which immediately fixed itself, and spun around to face the skeletons behind them.

Frisk had little room to move in her cage. She slid to the ground and crawled forward to try and to see what was happening beyond the bars. Sans and Papyrus had driven the human away from her location. Sans kept up the main offence and Papyrus would throw support in occasionally. It seemed difficult for him. Because he’s keeping the cage together, she realized, as Sans threw another wave of magic to keep them at a distance. The human was too good. Too good at dodging, at planning, and every time they were hit they barely seemed to flinch.

Frisk was terrified all of a sudden. They’d never leave her if she was trapped here, and it was only a matter of time before one of them slipped. She wanted to start over. She wanted to reset again, and figure something else out. She didn’t know what, but… Suddenly, Frisk felt something. It was determination, but somehow not her own. Something was with her, telling her to hold on, to not give up hope. Not just one voice, but many. She closed her eyes and tried to focus on those feelings.

“Be strong!”

“You’ll be okay!”

“Don’t give up!”

She recognized them. They were souls. The six human souls that Asgore had collected, and the same ones she had freed from Asriel in their final confrontation. They were in this world too. Six human souls. Could they help? Frisk tried to focus on her own soul. She tried to reach out with it and ask them to protect her friends and to help them escape. She could feel them there, but couldn’t read their answer. Then they began to fade and leave her. Frisk cried out as they vanished, pleading for them to come back. But she was alone now. She reached out and grabbed the bones of the cage, pushing against them. _Let me help them, please._ But the bars stood there, as solid as ever. She stopped pushing and let her head fall against them, trying to hold back tears.

Then she noticed the quiet. The sounds of fighting and impacts had vanished. They couldn’t have…Just as she was about to call out, the cage bars split open. Papyrus stood before her, looking down at her. The flickering portal light reflected off streams of sweat on his skull.

“Are you alright?” he asked her. She stood up quickly in response. “Sorry,” he apologized, “I didn’t mean to capture you. This time.” He tried to smile.

Behind him Frisk could see Sans, facing the portal with his arm outstretched.

“It,” he said through gasps of air, “It stopped…”

Across the room by the portal, Frisk could see the human. They were moving unnaturally. They would take a few struggled steps forward, then stumble back. She could hear sounds of frustration and effort from them. Next to them she could see the portal shaking erratically. She pointed it out. They had to hurry, but Sans stopped her as she passed him.

“Wait,” he said. She could see his outstretched arm quivering, like it was a strain just for him to be holding it out right now.

The human fell to their knees, struggling against some force Frisk couldn’t see. The portal rippled so violently, she thought it would break. Then it refocused.

“Sans, we have to try,” said Papyrus, stepping up beside them, “This may be our last chance.”

Sans did not seem consoled, but either due to exhaustion or acceptance of their situation, he let them lead him toward the portal. As they approached, Frisk felt the same presence she had in the cage. The souls. But this time they weren’t around her, they were around the human. She smiled. They had heard.

The human looked up at them. Their face was…Frisk couldn’t place it. They looked exactly like she did, but their expression was one she could not understand.

“They’re just sitting there,” said Papyrus quietly, “Come on, let’s go!”

Sans stood still, watching the human. He slowly raised his hand. Before his magic could fully take form, Frisk stepped in front of him and grabbed his arm.

“Why?” he asked her, his voice taking on a tone of anger she had never heard before, “Do you realize what this… _thing_ has done, Frisk?” She nodded. The empty tunnels. The dust. She could guess. But she didn’t let go, and he reluctantly allowed her to lower his hand.

Frisk heard a chuckle behind her, eerily similar to her own.

“Is this a joke?” said the human, “You’re sparing me?” Frisk turned toward them, watching their cold smile. She nodded. They laughed again. “Really? Is that so?” Their voice trailed off as they looked back to the ground. Then suddenly their smile vanished.

“What?” they asked, almost whispering, “Why can’t…” Their head snapped back up, glaring at Frisk. “You-“ They began to shake as their fury and voice grew. “You _took_ my _save_ spot!” They repeated it, almost screamed it as they attempted to stand, fighting against the invisible bonds that the six humans held them in. Sans pulled Frisk back as the human thrashed.

“Go,” he said simply. Papyrus took her other arm, and without another word, the three of them entered the portal.

**Notes for the Chapter:**

> 8D Back on this train again! We'll see if I can finish it this time.


	4. Chapter 4

The journey was as instantaneous as it had been the first time, but the tingle from before was replaced with a powerful shock that ran through Frisk’s body. Her legs buckled when they found the floor again but Papyrus held her up by the arm. On her other side she could hear Sans hitting the ground.

“Oh, thank GOD!” exclaimed Alphys.

“Finally! I was about to run in and drag you punks back!” shouted Undyne, “And Papyrus!! You’ve got a _hell_ of an explanation to give-” Her rant ended abruptly and within moments she appeared in front of them. “Hey, what happened?” Frisk was about to answer when she noticed pulses of pressure coming out of the portal behind them.

“Alphys, is that supposed to be happening?” asked Undyne. The portal fragmented, convulsing violently as if it were about to burst. Frisk was snatched up and pulled further into the room as the blue field shattered into a wave of energy and sparks.

Undyne lowered her gently to the ground as the explosion dissipated. Frisk tried to stay upright but her legs weren’t ready to listen. She fell against her rescuer’s knee.

“Careful,” said Undyne. She held Frisk steady as the child sunk to the ground. “Are you hurt?”

Hurt? She felt awful. Not just from the return trip. Her mind was rattled and full of questions. Most of these she wasn’t even sure she wanted to know the answer to. She hadn’t been fighting but she felt worn and weak. Swallowing, she shook her head “no”.

“Sans?” said Papyrus. Frisk looked over to see Sans lying limp in his brother’s lap. His eyes, or rather his sockets, were closed. Thoughts of the other human vanished from Frisk’s mind. She didn’t move as Undyne let go of her and moved towards the brothers.

“He doesn’t _look_ injured,” said Undyne, tilting his head to the side. Not on the surface, thought Frisk. “What about you?” Undyne asked. Papyrus started as she looked up at him, her eye unusually gentle. “You look exhausted. What happened in there?”

“I…um…” Papyrus broke eye contact, and looked over to Frisk as if asking her permission to talk about it. Frisk was still watching Sans.

After a few moments of silence, Undyne sighed and patted his shoulder. “It’s alright, you don’t have to tell me right now.”

“Sorry…”

A hint of humor returned to her voice. “Pap, I _just_ said it was okay.”

Frisk suddenly squeezed past Undyne, provoking a “hey”, to sit next to Sans. He was stirring. Papyrus followed her gaze and his face lit back up. Sans opened his eyes wearily. His pupils, dimmer than usual, wandered between the three of them before a tired, familiar grin appeared.

“Hey guys,” he said in a raspy voice.

Frisk asked if he was okay.

“Feel like I could sleep for the next decade, but other than that, yeah I’m okay.” His smile weakened as he let his eyes fall shut, but opened them again after a moment.“You okay?”

Frisk nodded.

“Do you need anything, Bro?” Papyrus asked him quietly.

“Just a nap, that’s all,” he answered. He looked between Papyrus and Frisk and gave a slow, genuine smile. “We all made it, huh?”

“Yeah,” said Papyrus, returning the expression.

All of a sudden Frisk felt like crying. _They really had all made it_.

“Well if you ask me,” cut in Undyne aggressively, “ _None_ of you look okay.” Her expression softened. “But I’m glad you’re all back in one piece.” She stood up and called to Alphys. “Alphys, can you take those observation accounts or whatever so I can throw these guys in bed?”

There was no answer from behind the counsel.

“Alphys?”

“Wh-what?” asked the scientist, peeking out at them. She had been focusing on her screen since the portal exploded. “Sorry, I was just- These readings are really weird.”

Undyne frowned. “As in…?”

“It’s like- well, the portal’s gone, obviously, but…i-it’s like there’s this weird instability where it used to be. It’s not HUGE or anything, but you know, I don’t know what it means yet.”

“Do you want me to stay and help you look into it?” offered Undyne. She looked uncertainly at the empty space in the middle of the portal frame.

“N-no, it’s fine. You guys go ahead and get some rest. I-I’ll finish up here,” said Alphys with a smile.

Papyrus helped his brother to his feet, and though he swayed a bit Sans seemed to be able to stand. Frisk pushed herself up on her feet as well. She turned to thank Undyne for the rescue earlier when the lights on the ceiling suddenly flared up and exploded. Not just the lights, but the screens, the electronics; every fragile device in the room went haywire. Alphys screamed. Frisk nearly fell back to the ground under the blast to her senses. It was terrifying and instantaneous. Within seconds the room was quiet again, curtained in darkness now with the occasional soft ‘clink’ of hot glass breaking the silence.

“Is everyone alright?” Undyne called out.

There were scattered sounds of confirmation. Frisk opened her mouth to ask if anyone knew what happened when her breath caught in her throat. What was that? There was a strange heaviness to her body, as if she was sitting on the bottom of a deep pool. She could still breath but it was difficult. What was the matter with her? She shook her head. Even the darkness around her seemed fog-like and unnatural.

“That was unusual.” said Papyrus, distracting Frisk from the weird feeling. “Should we try to find a light? Alphys?”

They waited for a moment but heard no answer.

“Doctor Alphys?” Papyrus called again. Frisk heard Undyne’s bootsteps rushing away from them, followed by soft talking that she couldn’t understand. Soon Undyne called back to them in a booming voice.

“GUYS, WE’RE LEAVING!”

“What’s wrong? Is everything okay?” asked Papyrus.

“Just _move_!”

Frisk looked for an exit and found that there was outside light peeking in from around the lab door. Undyne rushed past her in the dark heading towards it.

“Sans, are you okay?” Papyrus asked.

“I’m fine, Bro, I jus-…L-let’s just get out of here.” Sans sounded almost as disturbed as Frisk felt. The lab door opened and light from the hall filtered inside. It was dimmer than Frisk thought it should be. She could see the vague silhouettes of her friends moving before her as they headed towards the exit. Frisk stepped forward to follow them when something latched onto her soul. Everything vanished.

 

Papyrus turned into the hall and caught a glimpse of Undyne running ahead of him with Alphys cradled in her arms. The weird, weighty feeling he had experienced in the lab melted away as soon as he passed through the door. He paused just long enough to make sure Sans had come out with him. His brother looked exhausted but he was still able to move. Mostly. They traveled down the hall, up the stairwell and into the living room at the front of Alphys’s house. Only then did they catch up to Undyne.

She was kneeling with Alphys on her lap. The doctor was curled into a loose, trembling ball. There was a crack in her eyeglasses and she didn’t seem aware of her surroundings. Undyne shifted her arms so she could hug her. Alphys blinked at the secure embrace and her breathing began to slow.

“S-s-sorry about that. Th-thank you…”

Once Sans was up the stairs and resting against the wall, Papyrus approached them.

“Are you okay, Dr Alphys?”

She nodded as Undyne loosened her hold, allowing her to sit.

“What _was_ that?” he asked, looking back down the empty stairwell.

“Alphys?” said Undyne quietly, “Did you see anything?”

Alphys shook her head. “N-no. I didn’t see or even hear anything. I-it was just- I don’t know, it was this _feeling_ like…” Her brow creased as she tried to put it into words.

“Everything was hopeless?” suggested Sans. He was still winded from the escape.

“Y-yeah,” she said, “A-and I got really anxious like when…” She swallowed and didn’t finish her sentence, instead looking up at him. “Did- did _you_ feel it?”

“…Something like that,” he said quietly.

“Really?” asked Papyrus, “I just felt weirdly heavy. What about you Undyne?”

She shook her head. “No. Just the heaviness. Alphys, you sure your better?” she asked as Alphys pushed herself to her feet.

“Yeah,” she said smiling nervously, “Sorry I worried you. But now…” She twiddled her fingers in thought. “I’m n-not sure what to do. All of my equipment is in the lab. I’m sure…th-that is, my best guess is that it has to be because of the portal, because of that residual disturbance after we closed it.”

“How would the portal have caused this?” Undyne frowned, thinking back to it, “I mean, I could see it shorting out the lights, but there was something darker in there.”

Papyrus folded his arms and tilted his head, not sure what to think of any of this. He wasn’t worrying too much, of course. At least they had all gotten out.

“Bro?”

Papyrus looked up as Sans called to him.

“Where’s Frisk?”

“What do you mean? She’s-…Frisk?” Papyrus looked about the room expecting her to be standing to the side and listening, but there was no sign of the human child.

Alphys’s stutter worsened as she spoke. “Y-you d-don’t think she’s s-still in there?”

“ _Shit!_ ” Undyne sprang to her feet. She ran back into the stairwell and jumped off the steps halfway down. Papyrus almost matched her blasting speed as he followed her back through the hall. Had he really left Frisk back there? Of course he’d assumed she would be able to follow them. Why hadn’t she? Maybe she had been hurt in the fight and hadn’t told them. He’d been so preoccupied with Sans at the time. Before his thoughts could continue any further, they reached the lab door. Undyne had her hand on the doorknob.

“Papyrus,” she said warningly as he caught up.

“What’s wrong?”

“Are you sure you’re up to this? You guys just got back.”

“So did Frisk.”

“Yes, that’s my _point_!”

“Do we really have time to be talking about this?” asked a third voice. Papyrus looked to find Sans standing next to him. Undyne almost glared.

“I don’t need you passed out on me again,” she said.

“Relax. I’ll be careful.”

She snorted but shouldered open the door and stepped inside.

“Sans,” Papyrus began to protest, but his brother walked past him.

“C’mon Bro.”

The lab was as dark as it had been when they’d left it. Maybe even more, thought Papyrus. Was this fog? The moment they stepped through the doorway the light from the hall had dimmed.

“Frisk!” called Undyne as she continued forward.

“Frisk!” echoed Papyrus. His voice sounded muffled for some reason.

There was no answer.

“Come on Kid, say something,” muttered Sans as they walked.

“Maybe she found her way out already?” Papyrus offered hopefully. Undyne made a disgruntled sound.

Sans stopped walking with a jerk. “Ah?”

“What is it?” asked Papyrus. Sans was becoming harder to see. He was being engulfed by the black. “Sans?!” Papyrus sprang forward and reached to grab Sans’s coat, but his fingers passed through nothing but black fog. He flinched as a stabbing pain went through his hand and he recoiled. “ _Sans!”_

Undyne pulled him behind her. A spear materialized in her hand and she stabbed it downwards. It hit the lab floor with a clang and a flash of light. The fog retreated momentarily and the area around them was visible. Sans was nowhere to be seen.

**Notes for the Chapter:**

> @-@ This chapter was such a doozy. I rewrote the whole thing two or three times. And then had a creative block for most of the summer. A-anyway, here it is. Stuff's happening. Thank you everyone who's still reading, I really appreciate it.


	5. Chapter 5

**Notes for the Chapter:**

> Notes on reading the second half of this chapter:
> 
> Normal- Sans's perspective.
> 
> Italic- Frisk's perspective.

It hurt. Horribly. That was Frisk’s first thought when she came to. She was lying on a cold surface and couldn’t remember what had happened. Everyone was leaving the lab, then-Pain seized her, eliminating her thoughts. She clutched her abdomen and pulled herself into a ball as tears welled in her eyes. The pain wasn’t physical. Her soul felt like it was caught in a dozen hooks that were trying to tear her apart. After an agonizing minute the pain eased. Hesitantly, she sat up. There weren’t any repercussions. (She tried to figure out where she was. The space was more enclosed than the lab. It was practically black, but she could see tiny slivers like shreds of colored cloth that rose and vanished in the dark.)

Frisk could hear something. At first she thought it was white noise or electronics coming from the lab, but that wasn’t it. As her head cleared she realized they were voices; ones that she recognized. It was the six human souls. But now, instead of encouragement or hope, she heard fear, confusion, and pain. Their speech was barely coherent. The wrenching feeling from earlier seized her soul and she doubled over.

_Well. This is a problem, isn’t it?_ another voice spoke to her, so clear that she caught every word in spite of the pain.

_You’re determined. I suppose you would have to be to make it this far. But not a single EXP? You’re pretty lousy at this game._

Frisk squeezed her eyes shut. It hurt so much she could barely breath. Her voice was gone. What do you want? she thought as strongly as she could.

_Gee, I wonder,_ they answered with perceptible sarcasm, _I’m down a body, so that one’s high on my list. The extra souls don’t make up for that, if you were curious. They’re a mess. I think you owe me a body or two, considering this is all your fault_. Frisk cried out at the next stab to her soul. _If you’d stop being so damn stubborn about it._

They relented. Frisk opened her eyes and could see nothing but darkness with tiny flashes of color, but she couldn’t tell if that was her eyes or not.

_It’s not like you have to vacate or anything._ Their tone was almost bright. _We just need to give you some…reprioritization._

Frisk couldn’t understand what they were talking about. Her body and mind were so worn.

_It’s depressing how weak you are,_ they said with an exaggerated sigh, _Lucky for us, there’s an easy way to fix that._

Something clicked. No. She had to fight, to force them out. Even as the holds burrowed deeper into her soul and sent fresh, hot streams of tears down her face. Stay determined. Stay…determined…

_Look at that. The perfect fodder just walked in._

           

Sans awoke in darkness. Awoke? Had he been sleeping? He was standing when he came to. Wait, wasn’t he just with Papyrus and Undyne? Where were they? The space he was standing in felt different than the lab. Not too different. There was still that negativity clawing at his mind, but here it felt more enclosed. Looking closer, he found that the space held small fragments like shreds of colored cloth that flashed in and out of the black. That wasn’t any more comforting.

He tried to focus his thoughts. _Damn_ was he tired. The portal, the fight, the second fight, coming back, the black out, running out of the lab, running back _to_ the lab. Just thinking about it made him feel exhausted. He shook his head. There was no time to rest. Sans began walking forward but couldn’t tell if he was moving anywhere. Everything around him looked the same. He thought of calling for his brother or Frisk, but the heaviness of this place made him wary.

After just long enough for him to consider turning back, the space around him shifted and he saw something. A small body that lay crumpled on the ground. “Oh my God,” he breathed and broke into a run.

_Frisk could hear a voice shouting her name. A real voice this time, and one she knew. Sans? Someone had come. She would’ve laughed if everything didn’t ache so much. The torture had relented for the moment and she pushed herself up onto her hands and knees. One of her hands was gripping something she didn’t remember picking up._

She was moving, thank God.

“Frisk. Frisk, hey,” he said quietly as he reached her shaking body. He bent over to touch her shoulder.

Her arm flew up. Sans jerked back, narrowly avoiding the knife that would have sliced through his chest. “Kid, what’re-!” She leapt up and rushed at him. Again he barely managed to dodge in time. What was happening? She was acting like- Oh _no_. She came at him a third time. He was so exhausted. He knew he wouldn’t be able to move in time. She was nearly upon him. On instinct he conjured a wall of bones and blasted her back. She fell to the floor like a limp puppet. His regret was instant. This wasn’t the other human. This was Frisk. Frisk who had no health or defense or EXP. He should have been smarter than this.

See? _The voice was back. Not that Frisk could focus on it. With the strain of the hooks on her soul and now the crashing blow to her body, she wanted nothing but to pass out._ He just tried to murder you. You’re only defending yourself _. No. That wasn’t an excuse. She remembered that excuse. It wasn’t worth it._ He’s coming. You’d better get up _. She could hear Sans’s voice, but couldn’t understand his words. Everything hurt so much._ Get up _. No. She wouldn’t._ You idiot _, said the voice. She could feel their smile._ Who said you had a choice?

 Sans had his hand held out as Frisk rose. It was as if she was being pulled up on a string. She looked up and for the first time he saw her face. His determination faltered. Tears stained her cheeks. She was gasping. Terrified. Sans’ hand shook. “Kid, don’t make me…” She stepped towards him and his left eye flashed. Her soul was grabbed and thrown to the ground. Stay down, he thought, _please_ just stay down. She was struggling, forcing her way up again. The strain on her body was evident with each movement. He doubted that she would survive another hit. What did that demon _do_ to her? Something pulled strongly at Sans’s own soul and broke his concentration. Frisk and jumped to her feet to fly at him again, knife outstretched. The magic gripped his soul a second time and Sans was yanked backwards through the darkness and out of her reach.

**Notes for the Chapter:**

> Sorry this chapter's shorter but a lot went down. Also I was excited and wanted to get it out sooner. Might come back and edit a bit more later. The rest of the week's going to be busy. Thanks for reading!


End file.
